Downgrading the Great Dying

It makes for a dramatic narrative: Roughly 252 million years ago, a mass extinction event killed up to 96 percent of marine life, earning an infamous name in the geologic record, "the Great Dying." However, a new study suggests that this cataclysmic event has been overestimated. In the February issue of EARTH Magazine, read how a University of Hawaii paleontologist is improving our understanding of mass extinction events by exploring the effects of natural variability on background extinction levels, revealing a clearer signal in the noise.

To pinpoint the cause of a mass extinction event, other phenomena must be factored out. In the case of the Great Dying, this means figuring out how many extinctions can be attributed to the intense period of volcanic activity and how many are the result of natural selection and competition. Using statistics, Steven Stanley was able to revise the 96 percent extinction figure to 81 percent - still a serious extinction event, to be sure. To learn more about his methodology and the implications of the new study, read the full article in EARTH: https://www.earthmagazine.org/article/downgrading-great-dying.

The February issue of EARTH Magazine is now available online. Read about new research that suggests that grass and cropland fires produce more nitrogen pollution than wood-burning fires. Or learn how a multiagency study led by the U.S. Geological Survey is mapping the threats posed by solar storms to the domestic power grid. For these stories and more, subscribe to EARTH Magazine.

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Keep up to date with the latest happenings in Earth, energy and environment news with EARTH Magazine online at www.earthmagazine.org. Published by the American Geosciences Institute, EARTH is your source for the science behind the headlines.

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The American Geosciences Institute is a nonprofit federation of geoscientific and professional associations that represents more than 250,000 geologists, geophysicists and other earth scientists. Founded in 1948, AGI provides information services to geoscientists, serves as a voice of shared interests in the profession, plays a major role in strengthening geoscience education, and strives to increase public awareness of the vital role the geosciences play in society's use of resources, resiliency to natural hazards, and interaction with the environment.